Icemaker with piston-type ice remover



p 27, 1966 A. G. WElL ETAL 3,274,792

ICEMAKER WITH PISTON-TYPE ICE REMOVER Filed Sept. 16, 1965 5 Sheets-Sheet l Ma. Wm

Sept. 27, 1966 Filed Sept. 16, 1965 A. G. WEIL ETAL ICEMAKER WITH PISTON-TYPE ICE REMOVER 5 Sheets-Sheet 2 Sept. 27, 1966 A. G. WEIL ETAL 3,274,792

ICEMAKER WITH PISTON-TYPE ICE REMOVER 7 Filed Sept. 16, 1965 5 Sheets-Sheet 5 United States Patent O ICEMAKER WITH PISTON-TYPE ICE REMOVER Albert G. Weil, Walter A. Zeuschner, and Kenneth W.

Zeuschner, all of Chicago, Ill., assignors to Remcor Products Company, Chicago, IlL, a corporation of Illinois Filed Sept. 16, 1965, Ser. No. 487,710 11 Claims. (Cl. 62-138) This invention relates to icemakers and particularly to improvements in apparatus for making hard, clear ice and breaking the ice into bite size pellets.

A principal object of the present invention is to provide an improved icemaker and crusher which will produce pellets of hard clear ice.

Another object is to provide a continuous ice making and ice breaking device which is compact, of relatively simple construction and easy to dismantle for repair.

A further object of the invention is to provide a compact, economical device for making cracked ice to satisfy the particular requirements of coin-operated drink vending machines, self-service ice-vending machines, and the like.

More particularly, it is an object to provide an upright ice maker for forming a thick 'slabe of hard ice, moving the slab upwardly, breaking the slab, and discharging cracked ice from the top thereof.

Other objects and advantages of the invention will become apparent in the following detailed description.

Now, in order to acquaint those skilled in the art with the manner of making and using our improved icemaker, we shall describe, in connection with the acompanying drawings, preferred embodiments of the icemaker and preferred manners of making and using the same.

In the drawings, wherein like reference numerals indicate like parts:

FIGURE 1 is a vertical section of a preferred embodiment of the icemaker of the invention;

FIGURE 2 is a cross-section taken substantially along line 22 of FIGURE 1;

FIGURE 3 is a cross-section taken substantially along line 3-3 of FIGURE 1; and

FIGURE 4 is a vertical section of a modified form of the invention.

Referring now to the drawings, 10 designates generally an ice making unit. This unit would normally be housed in an insulated container (not shown) and is intended to be used in the vertical position shown. The unit 10 comprises generally a freezing chamber 12, evaporator coils 14 for conducting heat from the chamber, water feeding means 16, ice breaking means 18, ice moving means 20 for moving the ice into the ice breaking means, and sensing means 22 for discontinuing the freezing cycle and initiating the ice harvest cycle.

A base portion 24 supports the unit and is adapted to house a variety of pieces of equipment and to serve other functions as will be described.

In a preferred embodiment as shown in FIGURE 1, the freezing chamber 12 comprises a substantially vertical cylindrical freezer plate 26 made of a good heat conducting metal such as brass. This freezer plate is supported on and attached to the upper wall of the base portion 24, which is preferably formed of material having a relatively low coefficient of thermal conductivity.

Associated with, and in this particular embodiment surrounding, the freezer plate 26 are the evaporator coils 14. Operating means for circulating refrigerant through the evaporator coils 14 may be of the type described in the U.S. Patent 3,165,901, issued January 19, 1965. Such means includes, at least as main elements, a compressor and a condenser. As shown in FIGURE 1, the conduit ice 28 during a freezing cycle carries refrigerant from the con denser (not shown) through a receiver 30 and expansion valve or capillary tube 32 to the top of the coils 14, around the freezer plate 26 and back to the compressor (not shown) through conduit 34. The refrigerant circulating operating means also includes a hot-gas by-pass line 36 and a solenoid operated hot-gas by-pass valve 37 which function to supply hot gas to the coils 14 and thereby defrost the freezing plate 26, in the manner described in Patent 3,165,901.

The water feeding means 16 comprises a reservoir 38 formed in the lower part of the base portion 24. The reservoir is filled through a float controlled inlet valve 40 associated with water line 42. The water feeding means further includes a pump P which draws water from the reservoir 38 and a header 44 connected to the pump discharge. A plurality of substantially vertically extending water dispensing tubes 46a and 461) are connected to the header 44. In this embodiment, the tubes 46 are posi tioned outside of the freezing chamber and extend up into a secondary water reservoir 48 positioned near the top of the freezing chamber.

The reservoir 48 is formed of material having relatively low thermal conductivity, such as stainless steel and includes an annular base portion 50 extending substantially horizontally and radially outwardly from the freezer plate 26, an inner cylindrical wall 52 comprising a vertical extension of the freezer plate 26 and an angularly disposed sheet portion 54. It will be observed that a cross section of the reservoir 48 takes the form of a right triangle, portions 50 and 52 forming the legs and portion 54 forming the hypotenuse. An outlet 56 from reservoir 48 is formed at the apex of the triangular cross-section so that when the reservoir 48 is filled, water flows over the top edge 58 of the wall 52 and downwardly over the freezer plate 26.

Outlets 60 from the dispensing tubes are positioned near the base of the reservoir 48 and the water discharged therefrom is directed substantially tangentially with respect to the cylindrical plate 26 and wall 52. The outlets from dispensing tubes 46a and 46b are then directed to give the water a swirling motion so that as the water streams through circumferential outlet 56 it will flow down the freezing surface in a curved path and with evenness of flow over the whole surface.

The ice breaking means 18 comprises a crusher rotor 62 and an ice sizing ring 64 positioned at the top of the secondary reservoir 48. The rotor 62 (FIGURE 2) comprises a hub portion 66 and a plurality of blades 68 which in the preferred form have the ends thereof curved in the direction opposite the direction of rotation so as to provide a wedge-like crushing action. The rotor hub 66 is mounted on a drive shaft 70, as by means of complerneigtal non-circular portions so as to be rotatable therewit The ice sizing ring 64 comprises a cover plate 72 which has depending therefrom a plurality of breaker and sizing bars 74 spaced about the circumferential edge of the cover plate 72 and in close proximity to the circular path of the edges of the rotor blades 68. The lower ends of the bars 74 are attached to a flat circular ring portion 76 forming a part of the secondary reservoir 48, whereby a vertically extending circumferential ice discharge opening is defined. With the ring 64 thus attached to the cylinder 26-52, a bearing 73 may be formed at the center of plate 72 for rotatable support and guidance of the upper end of drive shaft 70.

Circumscribing, and preferably formed integrally with the reservoir 48, is an annular trough or tray 92 for receiving cracked ice from the crusher outlet, the inclined wall 54 of the reservoir serving to guide the ice from the outlet into the trough. Operating within the trough are a plurality of paddles 90 for sweeping the ice to a discharge chute 94 leading from the trough to an ice storagebin or the like (not shown). The paddles 90 are interconnected by a common spider or sweep arm 88 which bridges the crusher and is attached to the shaft 70 for rotation therewith.

The shaft 70 extends downwardly through the center of the freezing chamber and through a supporting platform 78 of the base portion 24 to a shaft driving motor M. The platform 78 may, if desired, be formed to define a support bearing for the lower end of the shaft, and the motor M is secured to the lower side of the platform by a plurality of brackets 80.

The shaft 70 has screw threads formed thereon over the major portion of its length, which threads may for example be of Acme type. The upper portion 71 of the shaft is unthreaded for a purpose which will be made more apparent.

Threadedly engaging the shaft 70 is a lift plate 82 substantially circular in form and normally positioned in the lower portion of the freezing chamber closely adjacent the supporting platform 78. One or more vertically extending guide bars 84 are secured to the inner surfaces of the plates 26 and 52 and each co-operates with a respective slot 86 in the lift plate 82 to retain the plate against rotation while accommodating and guiding vertical movement thereof. Preferably, the guide bar is made of a relatively low heat conducting material such as stainless steel or a plastic to deter formation of ice thereon. When the motor M drives the shaft 70, the lift plate 82 thus moves up or down on the shaft depending on the direction of rotation of the motor.

The thermostatic sensing means 22 comprises a vertically extending water scoop tube 96 which has an inlet 98 in the freezing chamber. The tube 96 extends through the supporting platform 78 and has an outlet 100 in the reservoir 38. Disposed in the tube 96 at a location below the freezing chamber is a thermal element 102 which extends through the tube 96 to suitable controls for switch connections to an electrical timer (not shown) which operates to control the water pump P, the solenoid operated hot gas valve 37 and the motor M, as described in Patent 3,165,901 and also our copending application Serial No. 277,914, filed May 3, 1963. The scoop tube 96 is positioned a predetermined distance radially inwardly from the freezer plate 26 according to the thickness of the slab of ice to be formed on the freezer plate.

The base portion 24 is a generally enclosed structure comprising the water reservoir compartment 38 and an upper equipment compartment 106 separated from the reservoir 38 by a horizontal floor section 108. The equipment section 106 houses a number of items already referred to including the water pump P and its associated discharge header 44, and the motor M. A drain pipe 114 leading from the freezing chamber 12 extends through the equipment compartment 106 and discharges into the reservoir 38. Thus any water descending through the freezing chamber which is not frozen finds its way back to the reservoir 38.

A plunger 136 is slidably mounted in an axial bore in the shaft 70, the plunger extending to adjacent the bottom of the freezing chamber and including a cross bar 142 extending through and slidable in a transverse slot 140 in the shaft below the lift plate, so as to be engaged by the lift plate as it travels downwardly on the screw thread. The plunger 136 extends upwardly above the upper end of the shaft 70 and is there engaged or operatively associated with a switch 110 which functions as a limit switch for the downward movement of the lift plate 82, the switch operating to stop the motor M before the plate reaches the bottom of the shaft thread. The plunger is normally biased upward to a switch closed position by spring means embodied in the switch or by a plunger biasing spring 137.

As a safety feature, in the event the switch should fail to shut the motor M off, the lower end of the shaft 70 is reduced and unthreaded, at 139, for a distance equal to the thickness of the nut or threaded portion of the plate 82, whereby the plate may travel downwardly off the thread and idle harmlessly until the malfunction is observed and corrected. Then, the spring 137, rod 136 and cross bar 142 will tend to shift the plate toward the threaded part of the shaft and cause the plate to re-engage the thread when the shaft 70 is rotated in plate raising direction.

The upper end of the ice maker, especially the ice collecting trough 92 and chute 94, are preferably closed by a removable cover.124. For convenience, the limit switch 110 is mounted on the cover in a position to cooperate with the plunger 136.

Operation The operation of the unit is electrically controlled and the electrical circuitry includes a timing device which together with the sensing means 22 controls the freezing,

defrost and harvest cycles.

The unit functions as follows, starting with the components in the positions. shown in FIGURE 1, the motor M deenergized and refrigerant being supplied to the coil 14: The water pump P draws water from the reservoir 38 and discharges water through the dispensing tubes 46a and 46b into the reservoir 48. The water is discharged in a swirling motion and spills over the top edge of the plate 52 through the circumferentially opening 56. As the water swirls downwardly over the inner surface of the refrigerated plate 26, a layer of ice is formed on the plate 26 (but not on the plate 52). As the water continues to flow downwardly over the plate 26 and the ice forming thereon, an essentially cylindrical slab of hard clear ice is built up on the wall of cylinder 26, excess water flowing back to the reservoir 38 through drain 114.

When the slab attains a predetermined thickness, as determined by the radial position of the water scoop tube 96, water begins to flow into the tube through the port 98 and over the terminal element 102. The element 102 upon sensing the temperature of the cold water is effective to operate the electrical timer (not shown).

The timer upon energization thereof operates initially to stop the Water pump P, to stop the condenser cooling means and to open the hot gas valve 37 to send hot gas rather than coolant through the coils 14. The valve 37 is held open for a predetermined time or until a predetermined gas pressure is attained in the coils, thereby to heat or defrost the plate 26 and free the cylindrical slab of ice therefrom.

Upon completion of the defrost cycle, the hot gas valve 37 is closed and the motor M is started to start the harvest cycle. When the motor M is energized, the shaft 70 and crusher rotor 62 are rotated in the direction indicated in FIGURE 2, and the lift plate commences to move upwardly on the threaded shaft. As it moves upwardly, the lift plate 82 pushes the cylindrical slab of ice upwardly into the path of the rotating crusher rotor 62, the arms of which chop or crack the ice be tween the wedge portions thereof and the breaker bars 74 and expel the cracked or c'rushed ice through the sizing ring 64. The rate of rise of the thread on the shaft is such that the cylinder of ice is raised on each revolution of the shaft by a distance no greater than the height of the sizing ring 64, whereby the ice is cracked into bite sized pellets and discharged to the trough 92. The paddles 90, rotating with shaft 70, then push the ice to the chute 94 which leads to a point of use, a storage hopper, or the like.

As the lift plate 82 moves upwardly, it closely approaches the crusher rotor 62 to cause complete crushing and discharge of the slab of ice. As it reaches the reduced and unthreaded neck portion 71 of the shaft 70 immediately below the crusher, the plate runs 01f the thread on the shaft and stops its upward ascent. Thereafter, in accordance with the preset timing arrangement, the refrigerant supply and the water pump are restarted and the direction of rotation of the motor M and the shaft 70 is reversed. The lift plate 82 is thereupon automatically re-engaged with the thread on the shaft 70 and starts to travel downwardly back to its normal position at the bottom of the freezing chamber 12. As the plate approaches bottom, it engages cross bar 142 and pushes the bar and the plunger 136 downwardly to actuate switch 110 to open position, where upon the switch operates in a manner readily apparent to those of reasonable skill in the art to stop the motor M. The apparatus is thus returned to its original condition to repeat the complete cycle of freezing, defrost and harvest.

The structure shown in FIGURE 1 can, of course, be made in a variety of sizes depending upon the space available for it and the amount of ice to be produced. For any given production, the unit is extremely compact and efficient. For example, a 200 pound icemaker, i.e., producing 200 pounds of ice per 24-hour period, need embody a cylinder only twelve inches long and six sinches in diameter, the entire icemaker being only about twentyfour inches long and eight inches in diameter. To double production, it is only necessary to increase the cylinder diameter to ten inches. Obviously, either or both of length and diameter may be varied to provide any desired capacity in almost any reasonable size. The compactness of the unit, the upward movement of the slab of ice and the top discharge afforded thereby render the apparatus ideally suited for cold drink vending machines, self-service ice-vending machines, and many other uses.

Modified equipment A modified form of our ice-maker is shown in FIG- URE 4. Where possible, like numerals with an appropriate letter suffix will be used to designate parts similar to those in the first embodiment. The second embodiment is in all essential respects similar to the first, but there are some significant differences. First, the apparatus does not have a water reservoir near the top of the freezer plate but embodies water dispensing tubes 46c and 46d positioned inside the freezing chamber 12a and having at the top thereof outlets 60a so directed that water discharging from them hits the freezer plate on an angle approaching a tangent and thus has an opportunity to spread out smoothly and stream down the freezing surface in a curved path.

It will also be observed that the water dispensing tubes 46c and 46d serve, in conjunction with slots 86a, as guide bars for the lift plate 82a to constrain the plate against rotational movement, the tubes for such purpose being reinforced and secured to the wall of the cylinder 26a by plates or bars 840 and 84d.

Another difference is that the crusher rotor 62a and the upper surface of the lift plate 82a are of generally conical form to insure discharge of all of the ice through the sizing ring 64a.

A cover or top dome 124a is removably mounted on the sizing ring 64a above the crusher 62a, the cover including a bearing 73a for the upper end of drive shaft 70a, the ice sizing ring 64a includes an upwardly extending cylinder portion 128 which is slidably received in a complemental groove in the annular margin of the cover, and the cover is detachably secured in place on the ring by thumb screws 132 or the like.

In this embodiment, an upper limit switch 134 is attached to the cover 124a and is adapted to be actuated by a short plunger 136a slidable in a bore in the upper end only of the shaft 70a. A transverse slot 140a is formed in the shaft immediately below the crusher, the slot receiving a cross bar 142a attached to the plunger 136a. The cross bar 142a projects beyond the periphery of shaft 70a and is thus exposed to be engaged by the lift plate 82a at the limit of its upward movement, whereby to push the plunger 136a upwardly to actuate the switch 134.

The switch 134 could be a double-acting switch for defining both the upper and lower limits of movement of the lift plate, and the switch actuating plunger could be elongate as shown in FIGURE 1 and equipped with two cross bars (like 142 and 142a) at the opposite ends of lift plate movement for actuating the switch in opposite directions to reverse shaft movement at the upper limit and stop the shaft and motor at the lower limit. However, in the embodiment illustrated in FIGURE 4, a switch a is mounted adjacent the bottom wall of the freezing chamber and sealed therefrom by a diaphragm 112a, the switch being disposed for engagement by the lift plate to stop the motor M when the plate 82a approaches its lower limit of movement. Also, though not shown, the lower end of shaft 70a may be unthreaded to provide the safety feature of the FIGURE 1 embodiment.

In operation of the FIGURE 4 embodiment, water is drawn into the unit and discharged to the dispensing tubes in the same manner as in the FIGURE 1 embodiment. Water is discharged from the outlets 60a at an angle directly onto the freezer plate 26a as described above. Refrigerant is sent through the evaporator coils 14a to cause formation of an essentially cylindrical slab of ice. When a predetermined thickness of ice is formed on the freezer plate 26a, water begins to run over the thermal element 102a in the water scoop tube 96a. Just as in the first embodiment, the thermal element is effective to energize a timer which operates to stop water pump P, to open the hot gas valve and then start the motor M. As the shaft 70a is rotated the lift cone 82a rises to effect harvesting of ice in essentially the same manner as before.

When the lift cone 82a approaches the upper end of its travel, it pushes the cross bar 142a and plunger 136a upwardly to actuate switch 134. In this embodiment, the switch 134 reverses the direction of rotation of motor M and the lift cone 82:: moves down the shaft until it engages the diaphragm sealed limit switch 110a which stops the motor M.

In essence, the second embodiment attains all of the advantages of the first, and the removable cover 124 facilitates vertically upward removal of all of the icemaker components to accommodate cleaning and/or repair. A similar removable provision could readily be incorporated in the first embodiment if desired.

In view of the foregoing, it is apparent that all of the objects and advantages of the invention have been shown to be attained in a convenient, practical and economical manner.

While we have shown and described what we regard to be the preferred embodiments of our improved ice maker, it will be appreciated that various changes and rearrangements may be made therein without departing from the scope of the invention as defined by the appended claims.

We claim:

1. In an icemaker: a tubular freezing plate defining a vertically disposed substantially cylindrical freezing chamber adapted to have an ice slab formed on the inner surface thereof, one end of said freezing chamber being open; means for flowing water downwardly over the inner surface of said freezing chamber in a substantially continuous uniform tangentially swirling cylindrical film; means for suppyling refrigerant to said freezing plate during a freezing cycle to form ice on the inner surface of said chamber and for supplying hot gas to said plate during a defrost cycle to loosen the ice from said surface; annular ice breaker means disposed adjacent and concentric with said open end of said chamber and including a rotary crusher rotatable about the axis of said chamber; crusher drive means including motor means and threaded drive shaft means extending axially through said freezing chamber; means for moving the formed ice into the path of said crusher including plate means movably mounted within said freezing chamber and threadedly engaging said shaft means for movement longitudinally of the chamber toward the crusher when said motor means drives said crusher; and means responsive to formation of a slab of ice for stopping the freezing cycle, starting the defrost cycle and starting said motor means.

2. In an icemaker: a freezing plate defining an upwardly open freezing chamber adapted to have an ice slab formed on the inner surface thereof; means for flowing water downwardly over the inner surface of said freezing chamber; means for supplying refrigerant to said freezing plate to form ice thereon; ice breaker means including a crusher rotatably mounted at the upper end of said chamber; means for moving formed ice into the path of said crusher including lift plate means mounted within said chamber for movement from adjacent the lower end of said chamber to adjacent said crusher; common drive means for conjointly rotating said crusher and moving said lift plate means; and means responsive to formation of a slab of ice on said freezing plate for stopping the supply of refrigerant and starting operation of said drive means.

3. In an icemaker as set forth in claim 2, reversing means for said drive means mounted adjacent the top of said chamber and disposed for engagement by said lift plate means for reversing said drive means and automatically returning said lift plate means to adjacent the bottom of said chamber, and drive stopping means adjacent the bottom of said chamber disposed for engagement by said lift plate means for automatically stopping said drive means when said lift plate means returns to the bottom of said chamber.

4. In an icemaker having a tubular freezing plate defining an upright substantially cylindrical upwardly open freezing chamber, means for flowing water over the inner surface of said plate for forming a slab of ice thereon, and means for periodically harvesting slabs of ice so formed; the improvement comprising ice breaker means at the upper end of said freezing chamber including a crusher rotatable about the axis of said chamber; crusher drive means including motor means and threaded drive shaft means connecting said motor means to said crusher and extending axially through said freezing chamber; means for moving formed ice to the ice breaker means including circular plate means threadedly engaging said shaft mean within said freezing chamber and adapted to move along said shaft means from adjacent the lower end thereof to adjacent said crusher when said motor drives said shaft means in one direction; and means operative upon crushing of the slab for reversing said motor means to return said plate means to the lower end of said chamber.

5. In an icemaker having an upright freezing plate, means for flowing water over said plate to form a slab of ice thereon, ice breaker means adjacent the top of said plate, means movable from adjacent the bottom of said plate to adjacent the top thereof for moving a formed slab of ice upwardly from said plate into said breaker means, and means for driving said slab moving means to the top of said plates; the improvement comprising rotary means for driving said slab moving means, a crusher in said ice breaker means connected to said rotary means to be driven thereby during movement of said slab moving means, and means for disengaging said slab moving means from said rotary drive means at the top of said plate to accommodate continued rotation of said crusher until the entirety of the slab of ice is crushed.

6. In an icemaker having an upright freezing plate, means for flowing water over said plate to form a slab of ice thereon, ice breaker means adjacent the top of said plate, and means movable from adjacent the bottom of said plate to adjacent the top thereof for moving a formed slab of ice upwardly from said plate into said breaker means; the improvement comprising a rotatable screw extending from adjacent the bottom of said plate to said breaker means, means threadedly connecting said slab moving means to said screw for movement by said screw, and means for reversely rotating said screw to drive said slab moving means from the bottom to the top of said plate and to return the same to the bottom of said plate, said screw having an upper end portion from which the thread is removed whereby the slab moving means may be released from the thread of the screw and idle harmlessly should the screw continue to be rotated in driving direction after the slab moving means reaches said breaker means.

7. In an icemaker as set forth in claim 6, said screw being hollow, a rod projecting through said screw and including portions extending to the exterior of the screw adjacent the bottom thereof and disposed for engagement by said slab moving means, and control means above said freezing plate operatively connected to said rod and to said means for rotating said screw for controlling the latter in response to the position of said slab moving means.

8. In an icemaker as set forth in claim 6, said ice breaker means including a movable crusher coupled to said screw and driven thereby, said unthreaded portion of said screw accommodating operation of said crusher by said screw after said slab moving means reaches said breaker means to insure complete crushing of the ice without damage to the icemaker.

9. In an icemaker having a tubular freezing plate defining an upright substantially cylindrical upwardly open freezing chamber, means for flowing water over the inner surface of said plate for forming a slab of ice thereon, and means for periodically harvesting slabs of ice so formed; the improvement comprising substantially circular ice breaker means at the top of said chamber, a lift plate movable within said chamber from adjacent the bottom thereof to said breaker means for moving slabs of ice to said breaker means, said lift plate having a generally conical upper surface extending axially into said breaker means and tapering radially downwardly toward said breaker means, and a crusher co-operable with and disposed within said breaker means and having lower surface portions complementary to the upper surface of said lift plate, whereby said lift plate co-operates with said crusher and said breaker means to insure complete crushing of the ice and complete discharge of crushed ice from said breaker means.

10. In an icemaker having a tubular freezing plate defining an upright generally cylindrical freezing unit adapted to have an ice-slab formed on the surface thereof; ice breaker means adjacent the top of said freezing unit; and means movable from adjacent the bottom of said unit to said breaker means for moving a formed slab of ice from said surface to said breaker means; the improvement comprising means for flowing water downwardly over said surface in a continuous substantially uninterrupted uniform tangentially swirling cylindrical film for formation of a hard clear slab of ice on said surface, said means including reservoir means surrounding and having a circumferential outlet disposed near the top of said freezing plate, and means for filling said reservoir in such manner as to impart to the water therein a swirling motion so that water flowing out of said outlet will move generally tangentially and swirl downwardly over said surface.

11. In an icemaker having a tubular freezing plate defining an upright generally cylindrical freezing unit adapted to have an ice-slab formed on the surface thereof; ice breaker means adjacent the top of said freezing unit; and means movable from adjacent the bottom of said unit to said breaker means for moving a formed slab of ice from said surface to said breaker means; the improvement disposed in the lower portion of said icemaker, and 10 threaded drive shaft means extending from said motor means to said crusher through said unit and threadedly engaging said lift plate, said motor means being reversible to move said lift plate up and down in said unit.

References Cited by the Examiner UNITED STATES PATENTS 11/1955 Kattis 62354 X 3/1960 Kohl 62348 X 6/1960 Raver 62354 X 12/1964 King 62354 FOREIGN PATENTS 6/1954 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

MEYER PERLIN, Examiner.

W. E. WAYNER, Assistant Examiner. 

2. IN AN ICEMAKER: A FREEZING PLATE DEFINING AN UPWARDLY OPEN FREEZING CHAMBER ADAPTED TO HAVE AN ICE SLAB FORMED ON THE INNER SURFACE THEREOF; MEANS FOR FLOWING WATER DOWNWARDLY OVER THE INNER SURFACE OF SAID FREEZING CHAMBER; MEANS FOR SUPPLYING REFRIGERANT TO SAID FREEZING PLATE TO FORM ICE THEREON; ICE BREAKER MEANS INCLUDING A CRUSHER ROTATABLY MOUNTED AT THE UPPER END OF SAID CHAMBER; MEANS FOR MOVING FORMED ICE INTO THE PATH OF SAID CRUSHER INCLUDING LIFT PLATE MEANS MOUNTED WITHIN SAID CHAMBER FOR MOVEMENT FROM ADJACENT THE LOWER END OF SAID CHAMBER TO ADJACENT SAID CRUSHER; COMMON DRIVE MEANS FOR CONJOINTLY ROTATING SAID CRUSHER AND MOVING SAID LIFT PLAT MEANS; AND MEANS RESPONSIVE TO FORMATION OF A SLAB OF ICE ON SAID FREEZING PLATE FOR STOPPING THE SUPPLY OF REFRIGERANT AND STARTING OPERATION OF SAID DRIVE MEANS. 